NASA Study Finds California Sinking Faster Than Sea Levels Are Rising

A new NASA-led research has found that California is sinking at a staggering rate of up to 20 cm annually due to over-extraction of groundwater, injection of wastewater, and natural tectonic forces. Researchers say this is not unique to California; land subsidence is a widespread global phenomenon that may seriously affect sea level estimates, flood hazards, and coastal engineering. As climate change and urbanisation deepen, learning about and resolving this crisis becomes more pressing.

Tracking the Rapid Sinking of California

NASA researchers used satellite radar technology to monitor land elevation changes across more than a thousand miles of California’s coastline. The study found that the Central Valley is among the worst-affected areas, with land sinking at an unprecedented rate. This phenomenon occurs as excessive groundwater withdrawal causes soil compaction, leading to land subsidence.

The situation is especially worrying because the land is sinking faster than the rising sea level, which increases the risk of flooding. The study highlights that regions facing subsidence could be more vulnerable to extreme weather events, putting communities and infrastructure at greater risk.

Global Implications of Land Subsidence

California’s land subsidence is part of a more significant global issue. Similar sinking trends have been seen in coastal megacities, especially those built on reclaimed land. Scientists warn that as the land sinks, it can worsen the impacts of rising sea levels, changing flood patterns and making urban areas even more vulnerable.

“In many parts of the world, like the reclaimed ground beneath San Francisco, the land is moving down faster than the sea itself is going up,” said lead author Marin Govorcin, a remote sensing scientist at NASA’s Jet Propulsion Laboratory in Southern California. His remarks highlight the urgency of addressing land subsidence globally, as it threatens infrastructure and increases the risks of flooding in coastal cities.

Projected Sea Level Rise and Coastal Risks

The study projects that by 2050, sea levels along California’s coast could rise between 6 and 14.5 inches due to the combined effects of melting glaciers, thermal expansion, and subsiding land. Localised projections indicate that some regions might see an even more significant rise of up to 17 inches, doubling previous estimates. This shifting landscape threatens the coast’s critical infrastructure, homes, and businesses. Experts emphasise integrating vertical land motion (VLM) data into sea level rise models to improve coastal planning and disaster preparedness strategies.

The findings stress the immediate need for sustainable water management, stricter regulations on groundwater extraction, and investment in land stabilisation projects. Scientists call for advanced monitoring systems to track land elevation changes and better predict long-term impacts. As the effects of land subsidence become increasingly apparent, policymakers, urban planners, and environmentalists must work together to reduce risks and strengthen resilience in vulnerable areas. Tackling this issue could help prevent future economic and environmental disasters tied to sinking land and rising seas.

References:

https://doi.org/10.1126/sciadv.ads8163

https://www.jpl.nasa.gov/news/nasa-led-study-pinpoints-areas-sinking-rising-along-california-coast

https://sealevel.nasa.gov/understanding-sea-level/global-sea-level/thermal-expansion

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